Heavy-duty self-locking sash balance

ABSTRACT

AN ELONGATED SASH GUIDE ADAPTED TO BE MOUNTED ON AT LEAST ON SIDE OF A WINDOW FRANE HAS A LONGITUDINALLYSLOTTED SPRING CASING TO ONE END OF WHIC IS SECURED ONE END OF A SASH BALANCING SPRING. CONNECTED TO THE OTHER END OF THE SPRING IS A SLIDE BLOCK PROVIDED WITH A TRANSVERSE BORE AND A PAIR OF PIVOT BOSSES ADJACENT THERETO. PIVOTALLY MOUNTED ON ONE OF THE PIVOT BOSSES IS A SHARPENDED LOCKING LEVER HAVING A CAM FOLLOWER ARM ON THE OPPOSITE END THEREOF. ROTATABLY MOUNTED IN THE SLIDE BLOCK BORE IS A ROTARY LOCK-OPERATING CAM OPERATIVELY ENGAGEABLE WITH THE CAM FOLLOWER PORTION FOR TILTING THE LEVER RELATIVELY TO THE CAM AND THEREBY MOVING ITS SHARP EDGE INTO POSITIVE LOCKING ENGAGEMENT WITH THE CASING. THE LOCKOPERATIVELY ENGAGEABLE WITH A TRUNNION KEY OF SIMILIAR TION OPERATIVELY ENGAGEABLE WITH A TRUNNION KEY OF SIMILAR CROSS-SECTION SECURED TO THE WINDOW SASH AND ROTATING THE CAM IN RESPONSE TO THE SWINGING OF THE WINDOW SASH RELATIVELY TO THE WINDOW FRAME OPENING AROUND THE TRUNNION KEY AS A FULCRUM. THE SLIDE BLOCK AND THE LOCKING LEVER ARE ADAPTED TO BE INTERCHANGEABLY MOUNTED ON OPPOSITE SIDES OF THE WINDOW FRAME BY REVERSING THE POSITION OF THE LOCKING LEVER FROM ONE PIVOT BOSS TO THE OTHER, BUT USING CAMS WITH OPPOSITELY-FACING RECESSES IN THE SLIDE BLOCK BORE.

m. H, 1971 D. M. mom 3,

HEAVY-DUTY SELF-LOCKING SASH BALANCE Filed Sept. 24, 1969 2 Sheets-Sheet 1 FIG! FIGWZ Z FIGII FIGS E M Fl 8261B Q //Z\ [34 0? Leg 0 do INVENTOR DONALD M, TROUT ATTORN EYS 3,611,636 HEAVY-DUTY SELF-LOCKING SASH BALANCE Donald M. Trout, 15750 Meyers Road, Detroit, Mich. 48227 Filed Sept. 24, 1969, Ser. No. 860,707 Int. Cl. 1E05d 15/22 US. Cl. 49-181 5 Claims ABSTRACT OF THE DISCLOSURE An elongated sash guide adapted to be mounted on at least one side of a window frame has a longitudinallyslotted spring casing to one end of which is secured one end of a sash balancing spring. Connected to the other end of the spring is a slide block provided with a transverse bore and a pair of pivot bosses adjacent thereto. Pivotally mounted on one of the pivot bosses is a sharpeuded locking lever having a cam follower arm on the opposite end thereof. Rotatably mounted in the slide block bore is a rotary lock-operating cam operatively engageable with the cam follower portion for tilting the lever relatively to the cam and thereby moving its sharp edge into positive locking engagement with the casing. The lockoperating cam contains a notch of non-circular cross-section operatively engageable with a trunnion key of similar cross-section secured to the window sash and rotating the cam in response to the swinging of the window sash relatively to the window frame opening around the trunnion key as a fulcrum. The slide block and the locking lever are adapted to be interchangeably mounted on opposite sides of the window frame by reversing the position of the locking lever from one pivot boss to the other, but using cams with oppositely-facing recesses in the slide block bore.

SUMMARY F THE INVENTION The invention particularly resides in the provision of the cam engaging a sharp-edged lever both of which are mounted on the slide block whereupon the sharp edge of the lever is urged into positive penetrating engagement with the channel sash guide in response to the rotation of the cam as a result of the tilting of the window sash out of its normal vertical plane; also in the provision of a separable coupling including a trunnion key on the sash and a key-receiving notch on the cam whereby the sash can be removed from the window frame yet the sash balance spring positively locked in the channel sash guide in response to the rotation of the cam; and also in the provision of a slide block having a pair of spaced locking lever fulcra upon which the locking lever can be mounted in order to adapt it to either side of the window frame so as to enable the use of the same locking device upon either side of the window sash without the necessity of providing separate right-hand and left-hand sash balance locking devices.

In the drawings,

FIG. 1 is a fragmentary vertical section through a doublehung tiltably-removable sliding sash window installation equipped with the heavy-duty self-locking sash balance of the present invention, taken along the line 11 in FIG. 2;

FIG. 2 is a fragmentary side elvation partly in vertical section of the sash balance installation shown in FIG. 1, taken along the line 2-2 therein;

FIG. 3 is a fragmentary horizontal section taken along the line 3-3 in FIG. 2;

FIG. 4 is a front elevation of one of the sash balance locking units shown in FIGS. 1, 2 and 3, removed from the sash and with the sash balancing spring omitted;

#FIG. 5 is a right-hand side elevation of the unit shown in FIG. 4;

3,611,636 Patented Oct. I2, 1971 FIG. 6 is a top plan view of the unit shown in FIG. 4;

FIG. 7 is a bottom plan view of the unit shown in FIG. 4;

FIG. 8 is a rear elevation of the unit shown in FIG. 4;

FIG. 9 is a front elevation of the rotary locking cam for the unit shown in FIG. 4;

FIG. 10 is a top plan view of the rotary locking cam shown in FIG. 9;

FIG. 11 is a rear elevation of the sash balance locking unit used on the opposite side of the window from that of FIG. 4;

FIG. 12 is a fragmentary front elevation, partly in section, of the sash-mounted cam operator, taken along the line 1212 in FIG. 1; and

FIG. 13 is a left-hand side elevation of the cam operator shown in FIG. 12, removed from the sash.

Referring to the drawings in detail, FIGS. 1, 2 and 3 show a double-hung tiltably-removable sliding sash window installation, generally designated 20, consisting of a window frame 22 within which two tiltably-removable upper and lower sliding sashes 24 and 26 are slidably mounted. Only the lower sash 26 is shown in FIG. 1, as the upper sash 24 is substantially a duplicate of the lower sash 26. Each sash 24 or 26-, as the case may be, has side rails 28 and is slidably, pivotally and removably mounted in a pair of combined sash-guide and balancing-spring lock units 30. Each sash 24 or 26 has the usual bottom rail 32 and top or meeting rail 34. The window frame 22 is provided with the usual side members 36 interconnected by top and bottom members 38 and 40 respectively, the letter being the usual slanting or downwardly and outwardly-inclined window sill. The window frame side members 36 are provided with inner and outer edge members 42 and 44 respectively which with the side members 36 form an elongated vertical recess 46 of rectangular or channel cross-section.

Resiliently mounted in each of the recesses 46 is a sash guide 48 which forms an element of the combined sash-guide and balancing-spring lock unit 30 for each sash 24 or 26. Each of the sashes 24 and 26 is conveniently of the double-pane type having double-pane units 50 for improved heat insulation. Such double-pane units 50 are conventional and are carefully sealed at their edges to prevent the entry of moisture or the circulation of air which would interfere with the insulating efliciency or vision through the window in extremely cold weather. Such double-pane units 50, however, add considerable weight to the window sash 24 or 26, with the result that the ordinary self-locking sash balance is incapable of operating satisfactorily, and has a serious tendency to slip when used with channel sash guides of plastic material, such as those formed of vinyl plastic. The slippery nature of such plastic enhances the tendency for ordinary sash balance locks to slip and therefore fail in their purpose.

Resilience is imparted to each sash guide 48 by elongated vertical resilient strip pads 52 of synthetic foam rubber or foam plastic adhesively secured to the frame side members 36 (FIGS. 1 and 3) and to the rearward wall 54 of the hollow spring casing or channel portion 56 of each sash guide 48. The spring casing or channel portions 56 are preferably of approximately rectangular cross-section and preferably formed integral with the front wall 58 of the sash guide 48, such as by being extruded unitarily therewith during production either from synthetic plastic material or from metal, such as aluminum. The front wall 58 has rearwardlyextending guide flanges 60 at its opposite edges for the purpose of engaging the inner surfaces of the window frame edge members 42 and 44 respectively. The inner guide flange 60 projects slightly beyond the edge member 44.

Each of the side rails 18 of the upper and lower sashes 24 and 26 is provided with a vertical longitudinal groove 62 with beveled opposite edges 64 (FIG. 3) which are engaged by the opposite edge portions or ribs 66 of V-shaped cross-section separated from one another by an elongated vertical front slot 68 running from top to bottom of the front wall 5-8 of each sash guide 48 at approximately the center of the channel portion 54 thereof. Each channel portion 56 has parallel opposite side walls 70 which connect its rearward wall 54 to the front wall 58.

Hooked over the upper end or edge '72 of each channel portion 56 of each sash guide 48 are the upper end loops 74 of two elongated sash balancing tension springs 76 (FIG. 1), the lower loops 78 of which are hooked into holes 80 (FIG. 4) in the upper end of a slide body or slide block 8 2 which forms one component of a self-locking slide, generally designated 84. The latter near its lower end is bored to receive a rotary lock-operating cam 86 (FIGS. 4 to 11 inclusive). Each locking slide 84 is vertically slidable within its respective channel portion 54 and its lock-operating cam 86 is rotatable to either lock the slide block 82 in its retained position or release it for free sliding motion in the channel portion 54 by the locking mechanism described below, depending upon whether the sash 14 or 16 is either removed from the window frame 22 or is slidably mounted therein.

The slide block 82 near its midportion and above the erably molded from suitable synthetic plastic, such as that known commercially as nylon, and for ease of sliding its web 88 is provided at its opposite edges with edge flanges 90 (FIG. 6), thereby causing the slide block 82 to possess an approximately H-shaped cross-section. The central portion of each slide block 82 is provided on one side with a longitudinal slot or passageway 92 communicating with a transverse bore 94 which rotatably receives the hub 96 of the rotary lock-operating cam 86 (FIG. 4).

The bore 94 at its rearward end possesses a counterbore 98 (FIG. 8) which rotatably receives the enlarged head 100 of the rotary lock-operating cam 86. The head 100 has an eccentric sector-shaped cam lug or projection 102 projecting axially therefrom near the periphery thereof with its arcuate outer edge 104 engaging the arcuate lower cam-follower edge portion 106 of a locking lever or pawl 108 (FIG. 8).

The slide block 82 near its midportion and above the bore 98 is provided with a pair of pivot bosses or projections 110 and 112 molded integral therewith and projecting rearwardly from the web or central wall 88 thereof. One of the pivot bosses 110 or 112 serves at a given time for pivotally mounting the locking lever or pawl 108 which swings therearound in accordance with the force exerted thereon by the cam lug or projection 102 or by the weight of the arm portion 114 of the lever or pawl 108, the underside of which is provided with the arcuate edge 106. The locking pawl or lever 108 is of roughly triangular outline with an arcuate upper edge 116 and an oblique forward edge 118 meeting at a sharp locking edge or end 120.

The slide block 82 and locking lever or pawl 108 are adapted to be used on either of the opposite sides of the sash window installation 20 and are interchangeable therewith, it being understood that the pivot boss 110 is used for mounting the locking pawl 108 on one side of the window (FIG. 8) and the pivot boss 112 for mounting it on the opposite side of the window (FIG. 11). The lock-operating cams 86, however, are not interchangeable since both are required to have a radial trunnion key recess or notch 122 of rectangular crosssetcion (FIGS. 2, 4 and 9) with a flared mouth 124 communicating with the groove or slot 92 in each slide block 82 and the notches 122 must both face the same direction when the sash 24 or 26 is to be removed.

Mounted in the vertical longitudinal groove 62 in each of the opposite side rails 18 of each sash 24 or 26 as by a nail or other fastener 126 is a trunnion key 128 (FIGS. 1, 2, 3, l2 and 13). Each trunnion key 128 has a base or attachment portion 130 which has beveled side edges 132 adapted to slidably engage the V-section ribs 66 on opposite sides of the slot 68. Projecting horizontally from the base portion 130 is a trunnion portion or key portion 134 of rectangular cross-section configured to fit snugly but removably into the notch 122 in the hub 96 of its respective lock-operating cam 86.

In the operation of the heavy-duty self-locking sash guide and balancing spring lock unit 30 of the present invention, let it be assumed that the working parts thereof are in the positions shown in FIG. 1 and the left-hand side of FIG. 2 with the pivot or trunnion keys 128 secured to the window sashes 24 and 26 and with the trunnion or key portions 134 thereof seated in their respective notches 122 in the rotary locking cam 86, with the mouths 124 of the notches 122 facing in a horizontal direction so as to close the slots 92 and retain the trunnions or key portions 134 in their respective notches 122. Either sash 24 or 26 is now in a position to be freely raised and lowered, with its weight at least partially counterbalanced by the tension springs 76. To remove either sash, the operator grasps the upper rail or meeting rail 34 thereof and swings the upper portion of the sash 24 or 26 downward around the trunnion portions 134 of the trunnion keys 128. As a result of this action, the mouth 124 of the notch 122 of the rotary locking cam 86 moves from its horizontally-facing position (FIG. 4) to a vertical position (FIG. 2) when the sash has been swung downward and inward into an approximately horizontal position shown in FIG. 3.

The consequent rotation of the key or trunnion portions 134 on the opposite sides of the window frame 22 rotates the mouths 124 of the notches 122 thereof from their horizontal trunnion-retaining positions to their vertical trunnion-releasing positions, aligned with the slots 92 in their respective slide blocks 82. At the same time, this rotation of the cams 86 also swings their respective cam lugs 102 against the arms 104 of their locking levers or pawls 108, swinging these around their respective pivot pins or 112 to forcibly move the sharp locking ends into penetrating engagement with the adjacent side wall 70 of its respective channel portion 56 in the corners adjacent their respective rear walls 54. This action securely locks the self-locking slides 84 with their respective balancing s rings 76 in their tensioned condition. At the same time, the alignment of the notches 122 with their respective vertical slots 92 enables the operator to lift the trunnion portions 134 of the tunnion keys 128 out of the notches 122 and up the slots 92 out of the slide blocks 82. The operator tilts the sash 24 or 26 by raising one hand higher than the other, whereupon the operator removes the sash by pulling it out of the window frame opening while the sash is in an oblique or diagonal position relatively thereto.

To replace the removed sash in the window frame opening, the operator reverses the foregoing procedure by inserting the sash in a laterally-tilted position into the window opening, then swinging the sash into a horizontal position while pushing its trunnion portions 134 of its trunnion keys 128 downward through the slots 92 into the upwardly-facing notches 122 of the rotary earns 86 on opposite sides of the window. The operator then swings the sash upward into its normal vertical position within the Window frame, whereupon the consequent rotation of the locking cams 86 causes their respective cam lugs 102 to swing out of camming engagement with the arcuate lower edges of their respective locking levers or pawls 108. The consequent release of the arm 114 of each locking lever 108 permits it to drop downwardly by its own weight, causing the sharp locking ends 120 to move inward out of engagement with their respective sash guides 48, assisted, if necessary, by a slight push downward to release the sharp ends 120 from the slight indentations which they have made in the side walls 70 of the channel portions 56 of the sash guides 48. The sash is then free to move upward or downward in its sash guides 48, while the balancing springs 76, thus released, resume their weight-counterbalancing functions.

The present invention has the further advantage over prior self-locking sash balances that it positively locks the locking units or self-locking slides 84 against either upward or downward motion. Some prior self-locking sash balances lock only in an upward direction, unlocking when the sash is pulled downward when washing the pane or painting the sash frame without removing the sash from the window frame after swinging it into an approximately horizontal position. A further advantage of the present invention lies in the fact that the sharp ends 120 of the locking lever or pawls 108 engage the sash guides 48 in the corners of their respective channel portions 56, thereby preventing the sash balance locking mechanisms from spreading or deforming the sash guides by pushing their side walls outward, especially when made of synthetic plastic material. Moreover, the powerful action of the present sash balancing locking mechanism absolutely prevents slipping in the rather slippery vinyl sash guides coming into increasing use.

I claim:

1. A heavy-duty self-locking sash balance construction for a tiltably-removable sliding sash mounted in a window frame, said construction comprising an elongated sash guide adapted to be secured to at least one side of the window frame and having associated therewith an elongated hollow casing with an elongated longitudinal opening therein,

a resilient sash balancing instrumentality disposed within said casing and secured at one end thereto,

a slide body slidably mounted within said casing and connected to the other end of said instrumentality and having a transverse bore therein directed toward said opening,

a rotary lock-operating element rotatably mounted in said bore,

a locking member engaging said lock-operating element and movably mounted on said slide body for motion relatively to said lock-operating element and having a sharp edge movable into and out of penetrating locking engagement with said sash guide in response to the rotation of said lock-operating element,

and means adapted to be secured to a side of the window sash and extensible through said opening into operative engagement with said rotary lock-operating element,

said means being responsive to tilting of the window sash thereon relatively to the plane of the window frame for rotating said lock-operating 1 element and consequently moving said sharp edge of said locking member into penetrating locking engagement with said sash guide casing,

said means means comprising a trunnion key, said rotary lock-operating element having a trunnion key recess therein detachably receiving said trunnion key,

said slide body having a longitudinal passageway therein extending upward from said bore, said trunnion key recess being movable into alignment with said passageway in response to rotation of said rotary lock-operating element,

said recess comprising a radial notch with an open mouth so movable into said alignment with said passageway,

and said trunnion key recess and said trunnion key being of non-circular cross-section.

2. A heavy-duty self-locking sash balance construction, according to claim 1, wherein said locking member has a cam follower portion thereon, wherein said lock-operating element has a cam portion thereon operatively engageable with said cam follower portion, wherein said locking member is a lever having a pivotal connection with said slide body, and wherein rotation of said lock-operating element urges said cam portion into operative engagement with said cam follower portion and directly and positively swings said locking member around said pivotal connection and consequently forces said sharp edge into said penetrating locking engagement with said sash guide.

3. A heavy-duty self-locking sash balance construction, according to claim 2, wherein said pivotal connection comprises a pair of pivot portions spaced apart from one another on said slide body, either of said pivot portions being adapted to pivotally receive said locking member in 0ppositely-facing directions thereof whereby to adapt said slide blocks and said locking member for interchangeable mounting upon either of the opposite sides of the window frame.

4. A heavy-duty self-locking sash balance construction, according to claim 1, wherein said trunnion key has an attachment base portion at one end thereof disposed substantially perpendicularly thereto and adapted to be secured to the side of the window sash.

5. A heavy-duty self-locking sash balance construction, according to claim 1, wherein said cam portion is disposed on the opposite side of said slide body from said recess.

References Cited UNITED STATES PATENTS KENNETH DOWNEY, Primary Examiner U.S. Cl. X.R. 49--453 

